An Osteochondral Lesion of the Distal Tibia and Fibula in Patients With an Osteochondral Lesion of the Talus on MRI: Prevalence, Location, and Concomitant Ligament and Tendon Injuries

Abstract

OBJECTIVE. The purpose of this study was to evaluate the prevalence and common location of a coexisting osteochondral lesion of the distal tibia and fibula and of associated abnormalities of the ankle ligaments and tendons on MRI in patients with an osteochondral lesion of the talus (OLT). MATERIALS AND METHODS. A search of a database of MRI studies performed between July 2003 and January 2014 yielded MRI examinations of 297 feet with OLTs. Two readers reviewed the MRI examinations independently for the presence of an osteochondral lesion of the distal tibia and fibula and for concomitant ligament and tendon injuries. If an osteochondral lesion of the distal tibia and fibula was present, the reviewers also recorded the location (zones 1-10) and stage. Interobserver and intraobserver reliabilities were assessed using kappa statistics. The associations between a coexisting osteochondral lesion of the distal tibia and fibula and an OLT or a concomitant ankle injury were evaluated using the chi-square test. RESULTS. Readers A and B identified 61 (20.5%) and 47 (15.8%) coexisting osteochondral lesions of the distal tibia and fibula, respectively, with good interobserver (kappa = 0.73) and excellent intraobserver (kappa = 0.97) reliabilities. The most common location of a coexisting osteochondral lesion of the distal tibia and fibula was zone 4 (29.5%) by reader A and zone 2 (21.3%) by reader B. Stage I and stage IIA were common (> 85%). The frequency of osteochondral lesions of the distal tibia and fibula was not significantly different according to the location or stage of OLT. Abnormalities in the tibialis posterior tendon and in the anterior and posterior talofibular, calcaneofibular, and deltoid ligaments were significantly more common in patients with a coexisting osteochondral lesion of the distal tibia and fibula than in those with an isolated OLT (p < 0.05). CONCLUSION. A coexisting osteochondral lesion of the distal tibia and fibula is not rare on MRI in patients with an OLT and is related to a higher frequency of concomitant ankle ligament and tendon injuries.